Modded Mustang Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
666 Posts
Discussion Starter · #1 ·
Well finally got the car on the Dyno yesterday. They put 100 miles on it and motor was vibrating the whole time. So something's off balance and there gunna start looking into it tomorrow. It could be the clutch/flywheel, crank, balancer. Anybody ever run into this problem? I was looking forward to finally getting my car back tomorrow but guess not.
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #3 ·
Yea but a local shop put rit together and so far there paying for all of the problems that its having. So that helps alittle. There gunna check the balancer and the clutch flywheel 1st, any other ideas what it could be.
 

·
Turbo Maniac
Joined
·
437 Posts
Recheck the crank balance and weigh the rods and pistons, but holy cow, that is gonna be a PITA. Hopefully it is a bad balancer or flywheel.
 

·
Premium Member
Joined
·
4,253 Posts
Did MMR balance the rotating assembly? Did they provide a post-balance spec sheet? What was the ounce-inch tolerance?

Did they use the correct bob-weight amount to match your piston/ring/conn-rod/bearing setup?
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #6 ·
I'm looking at my build sheet right now. I'm not too familiar with this info it says the crankshaft is balanced the these weights. Pistons 358, piston pin 109, pin lock 2, piston ring 31, total rod608, rotary 425, insert 46x2. And its 28.35 grams to one ounce. If that's what your asking
 

·
Registered
Joined
·
2,043 Posts
What clutch set up is it? Reason I ask is McLeod RST and RXT twins have to be assembled by lining up the black paint marks on the separate components to achieve proper balance. That's an easy thing to overlook and not too bad to go back and fix.

I'm interested in seeing what gives here. Sorry to hear about this problem, I would be losing sleep.
 

·
Premium Member
Joined
·
4,253 Posts
I'm looking at my build sheet right now. I'm not too familiar with this info it says the crankshaft is balanced the these weights. Pistons 358, piston pin 109, pin lock 2, piston ring 31, total rod608, rotary 425, insert 46x2. And its 28.35 grams to one ounce. If that's what your asking
That is exactly what I am asking...you want to be balanced within 2 ounce-inches or better. Most shops will do better than that if they have a good balancing machine.

Balancing Machines by CWT Industries - Why Balance Crankshafts, Cranks, and Line Hones?

As Anthony suspects...if the engine is fine, my next area of emphasis would be on the clutch / flywheel. Check the paint marks on the McLeod and make sure everything is torqued to specification with Lok-Tite.

 

·
Registered
Joined
·
666 Posts
Discussion Starter · #9 ·
I'm running the spec steel flywheel, stage 3+ clutch. It came with a spacer but i didn't install it. Could that be something to look into? This was my 2nd clutch install so I might have missed something.
 

·
Registered
Joined
·
2,043 Posts
Doubt it's the Spec set up. There's really no way to screw that one up unless the flywheel just came new out of balance. Unfortunately, the odds are there's something going on with that MMR shortblock, but that's for your mechanics or MMR to decide. Good luck...keep us posted.
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #11 ·
Will do man
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #12 ·
I'm still waiting on the shop to get back to me. I talked to Mmr on Friday and they were pretty helpful I toldthem what was goin on and they said they are pretty sure its not the shortblock but if we coildnt figure it out to send them the motor so they could check it out for me.

Iv also been doin a lot of research and when I pulled the motor I threw in a bmr k member and a arms and from what iv read they do cause vibrations and some people have actually pulled them off cuz it gets so bad. I'm hoping this is the problem
 

·
Registered
Joined
·
375 Posts
The k-member can't cause vibrations other than the driveline angle changing but then you adjust the pinion angle to correct it.

People just notice the vibrations and noises more because the k-member will transmit more of them to the chassis of the car.
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #14 ·
I'm gunna try to make it to the shop sometime this week so I can see what there talking about. I'm trying to figure out if my cams would have something to do with it there pretty aggressive.
 

·
Registered
Joined
·
156 Posts
Got a Brenspeed B326 / FRPP 302 Stroked going into my 09. I had the BMR K-Member/A-Arms etc in with my stock 3V with no noticeable increase in vibrations. Going to be running BBR Stage 2 cams and should have the car back together by next week. I'll let you know if anything changes with shakes.

I am putting in a BMR lower radiator mount and the new CB004 brace that will connect the radiator mount to the K-Member.
 

·
Registered
Joined
·
2,043 Posts
I've got a built stroker motor and stage 2 cams...stock k-member. With those cams you can see the car wiggle when idling. No vibration once the rpm's increase though.
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #17 ·
Got a Brenspeed B326 / FRPP 302 Stroked going into my 09. I had the BMR K-Member/A-Arms etc in with my stock 3V with no noticeable increase in vibrations. Going to be running BBR Stage 2 cams and should have the car back together by next week. I'll let you know if anything changes with shakes.

Right on man thanks

I am putting in a BMR lower radiator mount and the new CB004 brace that will connect the radiator mount to the K-Member.
I've got a built stroker motor and stage 2 cams...stock k-member. With those cams you can see the car wiggle when idling. No vibration once the rpm's increase though.
See that's what I'm not sure if it vibrates only at idle or at certain rpm's. I'm hoping to get out of work early this week to go take a look at it
 

·
Premium Member
Joined
·
1,723 Posts
I'm interested to know what happened with this build too.
 

·
Registered
Joined
·
666 Posts
Discussion Starter · #20 ·
The vibration was caused by the clutch not installed right.

1.When the tuning started a month and a half ago we just kept running into a bunch of problems.
First issue was maxed out the mafia, so we replaced it was a different one and relocated to the 3 1/2 in pipe coming down off the throttle body.

2. We got back to tuning and had spark blowout around 5500 rpm's so we re gapped them didn't work so we ordered a boost a spark and if fixed the issue.

3. Then we started working on the top end of the tune we ran into another problem. When it would get around 19-20 psi the bracket that holds the blower would start to flex under load so we had to make a bracket goin from the procharger bracket to the fender to hold it in place.

4. Finally got the tune set and finally running pretty good, I got a call on Thursday I was expecting to go pick it up that day but while they were running it on the dyno the cog pulley on the crank there's a pin in there holding it in place that just sheered off so we working on that right now. From what the shop told me and procharger told me this happens very rearly but the reason it happens is cuz on the 3 valves the snout on the crank is not as long on them as it is on the 2-4 valves so the cog pulley is usually not on all the way, so my 2 options were replace the crank with a longer snout or fabricate something on it right now , which they have done a lot on a couple ls1's.

It's been just a big headache since its goin into the shop, just running into problems all the time, they said they could get it done by next Friday so we will see, Il keep u guys updated.
 
1 - 20 of 24 Posts
Top